In the contemporary electrical energy economy, a component of inefficiency in energy consumption comes from “Rejected Energy.” Most rejected energy allegedly comes largely from two sources: transportation use of petroleum, and losses in centralized electricity generation and transmission. As hybridized and fully-electric transportation vehicles begin to migrate from vehicle-internal burning of petroleum-fuel to storage of at least some fraction of centralized-generated electricity, segments of the transportation use of petroleum sector shift to the centralized-generated electricity sector.
FIG. 1, adapted from the Lawrence Livermore National Laboratory report available at https://flowcharts.llnl.gov/content/energy/energy_archive/energy_flow_2012/2012newUSEnergy.pdf, depicts representative aspects of contemporary energy usage in the United States. From the fuels and source delineated on the left side the diagram, at least in 2012 the combination of Natural Gas, Coal, Biomass, and Geothermal, and Solar used for electrical generation total to 38.1% of overall energy fuel/conversion usage (38.1%) and all but a portion of Solar (overall being <0.235%) of this is directed to the powering of steam turbines for centralized electricity generation. Thus, a tremendous if not dominant opportunity to improve the efficiency of centralized electricity generation (and decentralized replacements/supplements to centralized electricity generation) could be obtained by sufficiently improving the efficiency of steam-turbine methods used for converting heat to electricity.
Thus, there is an important need for improving the efficiency of steam-driven electricity generation at centralized and medium-scale decentralized electricity generation plants.
The present invention is directed to improved-efficiency of steam-driven electricity generation at centralized and medium-scale decentralized electricity generation plants.
The present invention comprises multiple stages of shaft-less ring-shaped turbines, each ring turbine serving as a steam-driven magnetized rotor of an AC electrical generator and rotating without synchronization.
FIG. 2 depicts an example novel ring turbine rotor within a (partially cut-away) enclosing stator used to confine (and in some embodiments direct) the flow of steam. This example implementation depicted comprises spiral steam channels winding over the rotor surface as shown, although other steam channel and steam routing structures are possible, anticipated, accommodated, and provided for in the invention. Such a ring turbine rotor arrangement can, for example, be replicated as a stage in a multi-stage implementations provided for by the invention, including with varying scale from stage to stage to more optimally exploit steam energy capture as the multi-stage steam path varies from the effects of preceding stages. The novel shaft-less ring turbine can operate with much wetter steam resulting from its geometry and associated abilities to operate at lower steam velocity than traditional turbines require.
FIG. 3 depicts two perspective views of an example multistage embodiment of the present invention, illustrating example relative stage diameters varying from stage to stage as per steam energy capture design aspects of the invention.
By way of comparison, FIG. 4 depicts a representation of a traditional boiler-fed steam driven turbine arrangement comprising a heat radiator for extruding waste heat and a return pump.
In contrast, FIG. 5 depicts an adaptation of the boiler arrangement of FIG. 4 in accordance with some aspects of the present invention wherein the heat radiator and extrusion of waste heat are omitted. In some embodiments of the invention it can be advantageous to include a radiator after the turbine or turbine sequence, but such a radiator can be smaller than it would be in a traditional turbine system.
In a broader system view, FIG. 6 depicts an example schematic representation of steam, air/exhaust, water, heat, electrical, and boiler-heating fuel or thermal energy flows in an example embodiment of the present invention. It is noted, however, that the present invention typically need not involve the pressurized boiler design, and further can be invariant to the underlying heat source. Less efficient variations are possible that include a radiator to dispose of waste heat as provided for by the invention.
The boiler-heating fuel or thermal energy source can be a fossil fuel, bio-mass fuel, thermo-nuclear (fusion, fission, or other), geo-thermal capture, solar energy capture, etc. The resulting multiple-stage shaft-less ring turbine system is inherently more efficient that traditional turbine-driven electricity generation for several reasons including:                a. The novel shaft-less ring turbine can operate with much wetter steam due to its geometry and lower steam velocity.        b. Using a vacuum pump, some ring stages in the turbine can operate at vacuum pressure. Steam that is too wet to use in a ring can be converted to water by raising the pressure back to atmospheric pressure instead of cooling the steam with a radiator.        c. Waste heat can be recycled for further conversion to electricity rather than being rejected into the atmosphere.        
The omission of a shaft allows the steam path to be far more constrained and alternate energy-capture geometries to be used. For example, in a representative implementation of some embodiments, a ring turbine of a stage is arranged so that steam passes through inlet nozzles, pumps or injectors into narrow channels on the surface of the ring turbine into the gap between the ring turbine (rotor) and its enveloping housing (stator). If a shaft existed, then fins, spokes or blades must extend from a center, this entire region could not be sealed from the steam movement.
Additionally, the resulting arrangement can be arranged to provide tightly constrained paths that permit intimate-co-design to optimize across physical laws of motion, electromagnetism, thermodynamics, and steam behavior in a way that energy transfers efficiently and predictably from heat to steam to kinetic energy to magnetic energy to electrical energy.
In an example embodiment, each ring-shaped rotor is rotationally-suspended within an enveloping toroidal stator chamber comprising an interior toroidal cavity to accommodate the ring-shaped rotor, with room for a gap between the exterior surface of the rotor and interior surface of toroidal cavity within the toroidal stator. Thus, each ring-shaped rotor is a toroid without an attached or otherwise associated rotation shaft employed by conventional turbines.
In an example embodiment, pairs or other pluralities of associated electrical coils can be mounted on each stator, and these electrical coils can be used to convert energy from the moving magnetic field sources into electricity. Additionally, electrically-created heat from Ohmic losses in the electrical coils can readily put back into the system.
In some embodiments, the electrical coils can be used to control aspects of the rotors rotation and rotational stability.
In an example embodiment, AC currents are independently generated by each pair or other pluralities of associated electrical coils, and can be arranged to be single-phase or phase-locked multi-phase at a frequency determined by the rotation speed of the associated ring.
In an example embodiment, power electronics can be used to convert AC currents generated by each stage into forms of DC or AC power suitable for use in standard, evolving, or future electrical power distribution.
In an example embodiment, the present invention would comprise a plurality of stages, each successive stage internally operating at consecutively lower operating steam pressures with wetter steam.
In an example embodiment, steam is passed from one stage to the next with steam nozzles, pumps or injectors, which both regulate the pressure between the stages, but also provide an angularly-directed flow of steam through the stator tubes at a moderate velocity to power the rotors without damaging them. Traditional turbine blade damage can potentially occur because of the high velocity of water droplets within the steam. The force-receiving blades comprised by the rotors can be arranged to move perpendicularly to the water droplets, while the rings are moving in the same direction as the steam, further lowering collision energy.
A traditional turbine must cool ‘waste’ or ‘rejected’ energy within the steam with a radiator before recycling it back into the boiler as water. This can also be the case in some embodiments of the present invention by design choice, although importantly in such circumstances the amount of waste steam is advantageously far lower.